Question about 1989 GMC Sierra

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89 GMC sierra only starts when tps and map sensor unplugged

I have replaced tps and checked all fire and fuel. replaced map sensor with another(not new but from working vehicle) and no change. Checked temp sensor, control module, and coil as well.

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  • ajax5
    ajax5 Feb 18, 2013

    update: also I have watched the injectors, they seem to loose pressure when I plug in the map or tps.

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6 Suggested Answers

6ya6ya
  • 2 Answers

SOURCE:

Hi there,
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Posted on Jan 02, 2017

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MNfisherman
  • 11896 Answers

SOURCE: my son's gmc 4.3l hesitates upon acceleration. I

do you have any check engine lights on? If you do, that is the first thing I would have checked. It does sound like plugged EGR, vacuum leak, or bad TPS

Posted on May 15, 2009

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  • 1 Answer

SOURCE: 97 gmc sierra no fuel no spark replaced ign module

1996 GMC 1500 Pickup.
Replaced Coil, Dist cap/Rotor, Ign Mod & pick-up.
All showed to be bad with OHM meter.

20A ECM-B fuse keeps blowing out and I'm afraid to burn these new parts up....

ANY IDEAS OUT THERE???

Posted on May 19, 2009

mkv0525
  • 358 Answers

SOURCE: I have 96 gmc 350 vortec. missing really bad. Ive

ou need to check compression on all the cly. do you know which cly is dead?

Posted on Jun 12, 2009

  • 1168 Answers

SOURCE: I have A 1991 GMC SIERRA, 350,no fuel no spark,

Do you have power to the injectors? One of the wires to the injector will come on for a couple seconds as soon as you turn the key to the on position.The computer controls the ground side. If you do not get power to one of them start looking for an open circuit. The same power source will also go to your ignition coil and ignition module. If you do not have power on the pink wire to the coil apply a temporary fused battery power source to it and give it a try, this will also power up the injectors.
Check it out and let me know.

Posted on Oct 29, 2009

Molson02536
  • 3854 Answers

SOURCE: 1991 4.3L GMC Jimmy S-15 will not start. Turns

You need 3 things.
Compression
Good hot blue spark to all plugs.
Good gasoline and proper fuel pressure. 13-13.5 lbs on your TBI
If you have all 3 then move on to injector pulse to both injectors.

Keep me posted and recheck your spark plug wire to make sure they are not crossed. firing order 1-2-3-4-5-6 cylinder # passenger side 1-3-5 front to back. cylinder # drivers side 2-4-6 front to back
distributor #1 is located at the 7 o"clock and rotates clock wise so next distributor post on the right working clock wise is #2. Good luck and hope this helps.

Posted on Jan 05, 2010

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1 Answer

My 89 gmc sierra surges when idoling on in drive i dont know where to start....


You need to start by going to autozone n get a free diag ck tell me what codes came out a lot of thinks can do that tps sensor low fuel pressure dirty trottle bode dirty fuel filter or any other senso map mass air flow I need the codes then I can help u good luck

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2006 GMC Sierra 2500 series replaced throttle body sensor and fuel pump getting fire and gas but will not start


Do you have spark at the spark plugs ? Also are there any lights lit on the instrument cluster , check engine , SECURITY ? What throttle body sensor did you replace ? TPS -throttle position sensor ! What engine does yours have because there are a few options for this vehicle , 4.3 , 4.8 , 5.3 , 6.0 L !

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My 1991 gmc sierra will start but i have to feather the gas if I can get it to idle, the MAP sensor needs to be unplugged. I have changed the MAP 3 times with spares I had around.


Changing parts is not a solution or fix

Testing a vehicle to find a problem is

Once a problem is found, then the solution is
usually there in front of you

It starts
Is the fuel pressure correct?
Feathering the gas,that would pertain to the TPS Sensor
Was that tested?
MAP-no control over that,do you have vacuum leaks
& were any of the maps tested & correct for your elevation
or vehicle specs

Spark Plugs Good
Rotor & Cap Clean
Vacuum Leaks?

Got an IAC Valve at base of throttle body to clean or replace?

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What is the function of map sensor


MAP MANIFOLD ABSOLUT PRESSURE, MEASURE INWARD AIR FLOW OF INTAKE MANIFOLD, WORKS WITH MAF, TPS O2 SENSOR, TO GIVE THE RIGHT FUEL AIR MIXTURE, FOR MAXIMUN FUEL ECONOMY AND PROFORMANCE.

Jun 08, 2013 | 1992 GMC Sierra

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I have a 90 GMC Sierra, 5.7 ltr, 2 wheel drive, 1/2 ton. I recently replaced the ESC module ,MAP sensor, and TPS, because they coded out... I also replaced the distibutor as well. I was running well this...


Try spraying a couple shots of carb spray down the throttle body while a helper cranks it over. If it starts and runs for a couple of seconds check fuel pressure and the resistance of the injectors.

I’m happy to assist further over the phone at https://www.6ya.com/expert/jeremy_d728a59f986299fa

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1 Answer

My 1192 gmc sierra idles correctly with the map sensor unplugged


did you clean the port before you replaced the iac valve, and measure the pntle before putting it back in, whenyou buy a new iac valve you can't assume the pintle(needle) is correctly placed. the pintle shldnt exceed 1 1/8 inch past the body seat, it can be pshed in by hand, then after it's pu t back in cycle ignition on for 10 second (do not start) then turn ign off for atleast 10 seconds, this allows the iac valve to reset. then start engine.

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I have a 95 GMC Sierra 1500 5.7L V-8. I am having problems starting and keeping it from stalling. It fires up at first then idles rough, then dies. When put in gear it dies immediately. I have replaced the...


Hi, you've hit the usual causes. Now check for vacuum leaks and also for an EGR valve stuck open.

Please see my tip at http://www.fixya.com/cars/r7427423-fix_poor_idle_high_idle_stalling_fuel . These are generic instructions. If you get stuck or need specific instructions for your car, please get back to me with model, year and engine info.

Jan 09, 2011 | 1995 GMC Sierra

2 Answers

1995 GMC Sierra


Just a thought, have you checked yout TPS(throttle position sensor)? I had similar problems with my 89 GMC Jimmy 4.3l, however a code 44 is strange. Also check to see if your problems go away if you advance the timing a few degree's.

Hope this helps

Jun 15, 2008 | 1995 GMC Sierra

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